What is a line editor, and how can you use it in your workflow? In this Weekly Iteration, George Brocklehurst and Chris Toomey explore Readline, the most common line editor. Learn how to use it in the shell, your REPLs, and even in your GUI.

This is a companion discussion topic for the original entry at


Thank you for the video about readline, I always wanted to learn more about it.

I ran into some issues, when I tried to follow your examples. I am using iTerm2 with zsh (and oh-my-zsh), and I cannot undo using Ctrl+. It prints ^ in my terminal. Ctrl+W, Meta+f, Meta+b, Ctrl+a, Ctrl+b is working fine, but all others kebindings don’t. By any chance, do you know what reason can be? I tried to google it, but nothing useful was found.

My guess is this has to do with how iTerm handles eacape sequences. They
expose configuration for various keys which can likely resolve this,
although I’m unsure of the specifics.

I’d recommend searching for iTerm and the key sequence that is giving you
trouble, and hopefully that will solve it for you.